You are looking at
91
-
100
of
1,534
items for
:

Digby Elliott, Kathryn L. Ricker and James Lyons

Fifteen participants practiced a two-target sequential aiming movement with either full vision of the movement environment, vision during flight, or vision while in contact with the first target. After 100 acquisition trials, participants performed a retention test in their own condition and then were transferred to each of the other two vision conditions. Both performance and kinematic data indicated that rather than becoming less dependent on visual information with practice, subjects learned to adjust their movement trajectories to use the visual information available in their particular vision condition. Although transfer to a degraded vision condition disrupted performance, when vision was augmented participants quickly adjusted their aiming trajectories to use the added information. The findings suggest that at least part of learning involves the development of rapid and efficient procedures for processing afferent information, including visual response-produced feedback.

The aim of the present study was to examine the effects of balance training with visual feedback on stance and gait in school-age children with hemiplegic cerebral palsy. Ten participants between 5 and 11 years of age were assigned to either the training or the control group according to an aged-stratified randomization. The training corresponded to three sessions per week during six weeks. Stance and gait parameters, based on force plate data, were assessed three times in both groups: (a) at the beginning of the study (before training); (b) after six weeks; (c) after ten weeks. Spatial and temporal parameters were calculated. The results for stance showed that the training improved the performances on the tasks that were trained. More interesting, the results for gait showed that the walking pattern became more symmetrical after the training.

Robert J. Vallerand

The purpose of this study was to assess the relationship between the amount of positive verbal feedback presented and the ensuing intrinsic motivation of male hockey players toward a hockey-related task. The subjects were 50 male hockey players 13-16 years of age who performed on an interesting task consisting of 24 slides that allowed the subject to test his decision-making abilities in simulated hockey situations. Subjects performed on the task and received either 6, 12, 18, 24 (on every trial or slide), or no positive verbal reinforcements regarding their performance. Following their participation on the task, subjects answered an intrinsic motivation questionnaire and a question on feelings of competence. Results indicated that subjects receiving positive verbal feedback displayed a much higher level of intrinsic motivation and experienced higher levels of feelings of competence than subjects in the control group, irrespective of the amount of feedback presented. Further, no other differences were found among the feedback groups. These findings are discussed in light of cognitive evaluation theory (Deci & Ryan, 1980) and previous intrinsic motivation studies on the effect of positive verbal feedback. Finally, implications and suggestions for future research within the realm of sport are proposed.

Michael A. Khan, Gavin P. Lawrence, Ian M. Franks and Digby Elliott

The purpose of the present study was to establish the contribution of visual feedback in the correction of errors during movement execution (i.e., online) and the utilization of visual feedback from a completed movement in the programming of upcoming trials (i.e., offline). Participants performed 2 dimensional sweeping movements on a digitizing tablet through 1 of 3 targets, which were represented on a video monitor. The movements were performed with and without visual feedback under 4 criterion movement times (150, 250, 350, 450 msec). We analyzed the variability in directional error at 25%, 50%, 75%, and 100% of the distance between the home position and the target. There were significant differences in variability between visual conditions at each movement time. However, in the 150-msec condition, the form of the variability profiles did not differ between visual conditions, suggesting that the contribution of visual feedback was due to offline processes. In the 250-, 350-, and 450-msec conditions, there was evidence for both online and offline control, as the form of the variability profiles differed between the vision and no vision conditions.

Increased knee flexion and decreased knee valgus angles and decreased impact ground reaction forces (GRF) are associated with decreased anterior cruciate ligament (ACL) loading during landing. The purpose of this study was to determine the effect of tactile feedback provided by a simple device on knee flexion and valgus angles and impact GRF during landing. Kinematic and kinetic data were collected when 28 participants performed baseline, training, and evaluation jump-landing trials. During the training trials, the device was placed on participants’ shanks so that participants received tactile feedback when they reached a peak knee flexion angle of a minimum of 100°. During the evaluation trials, participants were instructed to maintain the movement patterns as they learned from the training trials. Participants demonstrated significantly (P < .008) increased peak knee flexion angles, knee flexion range of motion during early landing (first 100 ms of landing) and stance time, decreased impact posterior and vertical GRF during early landing and jump height, and similar knee valgus angles during the evaluation trials compared with the baseline trials. Immediately following training with tactile feedback, participants demonstrated landing patterns associated with decreased ACL loading. This device may have advantages in application because it provides low-cost, independent, and real-time feedback.

David Sherwood, Keith Lohse and Alice Healy

Many research studies have shown the advantage of directing the focus of attention (FOA) externally as opposed to internally. However, it is not clear how the availability of concurrent visual feedback might impact attentional processes as the FOA is shifted between internal, external, relevant, and irrelevant sources of attention. The current experiment varied the FOA by asking the participants to judge joint angles (internal-relevant), respiration (internal-irrelevant), dart release angle (external-relevant), and tone loudness (external-irrelevant) at dart release in which task-intrinsic concurrent visual feedback was available or not. Spatial errors and trial-to-trial variability in the outcome were reduced when vision was available. Spatial errors were greater during internal judgments compared with external judgments particularly when vision was not available and when making judgments about task-relevant factors. A focus on irrelevant factors generally did not affect performance compared with relevant factors. These findings suggest that availability of concurrent visual feedback modulates focus of attention effects in motor control.

Background:

Increasing physical activity (PA) levels in older adults represents an important public health challenge. The purpose of this study was to evaluate the feasibility of combining individualized motivational messaging with pedometer walking step targets to increase PA in previously inactive and insufficiently active older adults.

Methods:

In this 12-week intervention study older adults were randomized to 1 of 4 study arms: Group 1—control; Group 2—pedometer 10,000 step goal; Group 3—pedometer step goal plus individualized motivational feedback; or Group 4—everything in Group 3 augmented with biweekly telephone feedback.

Results:

81 participants were randomized into the study, 61 participants completed the study with an average age of 63.8 ± 6.0 years. Group 1 did not differ in accumulated steps/day following the 12-week intervention compared with participants in Group 2. Participants in Groups 3 and 4 took on average 2159 (P < .001) and 2488 (P < .001) more steps/day, respectively, than those in Group 1 after the 12-week intervention.

Methods:

Adult residents’ 1-week accelerometer-measured physical activity and obesity status were measured before and after a new rail stop opened (n = 51 Time 1; n = 47 Time 2). Participants recalled the week’s walking bouts, described them as brisk (moderate) or not, and reported a rail stop destination or not.

Results:

At the end of the week, we provided accelerometry output to residents as a prompt. Recall of activity intensity was accurate for about 60% of bouts. Nonobese participants had more moderate bouts and more “stealth exercise” —moderate bouts recalled as not brisk—than did obese individuals. Obese participants had more overestimates—recalling light bouts as brisk walks—than did nonobese individuals. Compared with unprompted recall, accelerometry-prompted recalls allowed residents to describe where significantly more moderate bouts of activity occurred.

Conclusion:

Coupling accelerometry feedback with self-report improves research by measuring the duration, intensity, and destination of walking bouts. Recall errors and different patterns of errors by obese and nonobese individuals underscore the importance of validation by accelerometry.

Tom Sharpe, Hosung So, Hasan Mavi and Seth Brown

Based on sequential behavior analysis (SBA) approaches to clinical practice activities (Sharpe, Lounsbery, & Bahls, 1997) and on results from school-university collaboration approaches to teacher education (Sharpe, Lounsbery, Golden, & Deibler, 1999), this study analyzed the effects of different supervisory personnel and practice-teaching settings on the relative effectiveness of SBA feedback and goal-setting practices. Teaching performances of two matched groups of undergraduates (N = 4) were observed. An A-B-A-C multiple baseline design with a treatment reversal across participants was used. The B-phase consisted of school-based practice teaching, the C-phase consisted of peer-based practice teaching, and the multiple baseline represented the differing times in which the same SBA feedback treatment was administered. Results demonstrated substantial improvement in select teacher and student practices in the school-based setting but a limited effect in the peer-based setting. Participant response data provided additional support for school-based activities. This study endorses a collaborative field-based approach to teacher education and contradicts the literature in nonsupport.

Victor H. Mancini, Elizabeth K. Clark and Deborah A. Wuest

Both the short- and long-term effects of systematic supervisory feedback (SSF) using CAFIAS on the behaviors of a field hockey coach and her team were examined. The investigation was divided into four phases. During Phase I the coach was videotaped five times to provide baseline data. In Phase II the coach was videotaped nine times and was provided with SSF. At the conclusion of the intervention, five practices were videotaped for Phase III. One year later, in Phase IV, the coach was again videotaped for five practices. Descriptive statistics were calculated and comparisons were made between the behaviors exhibited in Phases I and III as well as Phases III and IV. Praise and information increased, and directions and criticism decreased from Phases I and III. These changes were evident 1 year later. This investigation demonstrates that even the behaviors of an experienced coach can be altered using SSF and that these changes can be sustained over time.